Philadelphia Eagles Blog - Go Iggles

September 20, 2012

In Praise of Analytical Humility

Professional football is a tremendously complicated endeavor. On any given play, there's stuff happening all over the field that even the most gifted coaches can't take in all at once. That's the reason teams do so much film study and why coaches after a loss will sometimes truthfully answer, "I'm not sure what happened there; we'll check it out when we watch the tape."

When I'm doing a video rewind, there's a reason I use the words "I think" or "it looks like" a lot. Without knowing for sure the actual play call -- what was supposed to happen -- we're left guessing the coach's intention by what actually occurred.

Sometimes this isn't too hard to do. Yesterday Sheil wrote about two great, lead-preserving plays by Brandon Boykin. All credit in the world to Boykin for execution, but we also need to credit Todd Bowles whoever's calling the coverages for some fantastic guesswork as well.

Here's the pre-snap alignment on the first play, where Boldin ran the 15-yard out from the right slot:

And the second play, where Jones went deep from the same spot:

Identical offensive formations, very similar defensive alignments. The one change is Boykin, who's well off the receiver in the second pic, or as some would say, "Juan Castillo isn't allowing him to play press."

But we can see immediate differences after the snap. Again, first play:

Tight coverages across the front of the defense, Ryans moving forward at the snap to pick up the running back, safeties dropping into deep halves. This is man under cover two defense. In contrast on the second play:

Notice that for some players, it looks like the same defense. Kendricks and Nnamdi are both in tight coverage on the TE and outside WR, respectively. But look at the other guys. Boykin is running as fast as he can backwards. Allen is within the hashes this time. And DRC is already coming off his man up top to pick up the leaking running back. This is a classic cover three zone defense, with Boyking coming out of the slot to be the third deep guy.

Back to the first play. Boykin can play aggressively on the out route, because he knows he has safety help over top:

Whereas on the second play he "is" the safety:

And as you can see at the time of the throw, that ball had no chance. Great play by Boykin to break it up, but great call by Bowlessomeone to have him back there.

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So those are two examples of where we can probably figure out what they were doing, if we watch the play enough times to take it all in. But here's one where we it's a bit tougher. Pre-snap alignment down by the goal line:

We run an awful lot of man coverage this year, and at the snap that at least looks like what Nnamdi's in again. Maybe we give him safety help, maybe we don't, but he's clearly locked up.

Oops, so much for that idea. As his man cuts inside, Nnamdi lets him go and drops deep. Looks like we're doing quarters coverage in the back and three across underneath -- maybe. If we are, then Ryans needs to come off the tight end (?) and pick up the crosser. Unfortunately, he doesn't and we get this:

Easy completion results.

Now, I watched the play a few times, so if I had to guess, this one is on Ryans. But it's possible Coleman was suppoed to invert with Nnamdi and he forgot and ended up in the wrong place. Without knowing the call, we know nothing for sure, other than that it wasn't "Nnamdi's man" who caught the pass.

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I feel bad saying something unkind about Ryans, because he's playing so well, so let's close with one more play that's better for him.

To cut the suspense, I'll say upfront I don't know what this coverage is. I think it's a cover four, with Nnamdi and DRC dropping to quarters, but it's also possible that it's zone on the close side and man up top. If I had to guess, I'd say cover four. Pre-snap:

I drew up the routes at the bottom since that's where the action is. Up top it's outside guy run off, TE and slot run outs underneath him. Beginning of routes:

DeMeco is locked up on his man while DRC is playing off. Flacco's looking right at DRC's receiver:

Damn those non-press coverages that give up the easy crossing routes. Except wait:

DeMeco comes off his receiver (passing him to the safety) and jumps DRC's. Flacco has to pull it down, and if you zoom in on the photo you'll see that was fatal, because T. Cole is about to swoop in from the blind side. Just a great play all around, and an indication of why we don't just run the same thing over and over.

Comments

In Praise of Analytical Humility

Professional football is a tremendously complicated endeavor. On any given play, there's stuff happening all over the field that even the most gifted coaches can't take in all at once. That's the reason teams do so much film study and why coaches after a loss will sometimes truthfully answer, "I'm not sure what happened there; we'll check it out when we watch the tape."

When I'm doing a video rewind, there's a reason I use the words "I think" or "it looks like" a lot. Without knowing for sure the actual play call -- what was supposed to happen -- we're left guessing the coach's intention by what actually occurred.

Sometimes this isn't too hard to do. Yesterday Sheil wrote about two great, lead-preserving plays by Brandon Boykin. All credit in the world to Boykin for execution, but we also need to credit Todd Bowles whoever's calling the coverages for some fantastic guesswork as well.

Here's the pre-snap alignment on the first play, where Boldin ran the 15-yard out from the right slot:

And the second play, where Jones went deep from the same spot:

Identical offensive formations, very similar defensive alignments. The one change is Boykin, who's well off the receiver in the second pic, or as some would say, "Juan Castillo isn't allowing him to play press."

But we can see immediate differences after the snap. Again, first play:

Tight coverages across the front of the defense, Ryans moving forward at the snap to pick up the running back, safeties dropping into deep halves. This is man under cover two defense. In contrast on the second play:

Notice that for some players, it looks like the same defense. Kendricks and Nnamdi are both in tight coverage on the TE and outside WR, respectively. But look at the other guys. Boykin is running as fast as he can backwards. Allen is within the hashes this time. And DRC is already coming off his man up top to pick up the leaking running back. This is a classic cover three zone defense, with Boyking coming out of the slot to be the third deep guy.

Back to the first play. Boykin can play aggressively on the out route, because he knows he has safety help over top:

Whereas on the second play he "is" the safety:

And as you can see at the time of the throw, that ball had no chance. Great play by Boykin to break it up, but great call by Bowlessomeone to have him back there.

---

So those are two examples of where we can probably figure out what they were doing, if we watch the play enough times to take it all in. But here's one where we it's a bit tougher. Pre-snap alignment down by the goal line:

We run an awful lot of man coverage this year, and at the snap that at least looks like what Nnamdi's in again. Maybe we give him safety help, maybe we don't, but he's clearly locked up.

Oops, so much for that idea. As his man cuts inside, Nnamdi lets him go and drops deep. Looks like we're doing quarters coverage in the back and three across underneath -- maybe. If we are, then Ryans needs to come off the tight end (?) and pick up the crosser. Unfortunately, he doesn't and we get this:

Easy completion results.

Now, I watched the play a few times, so if I had to guess, this one is on Ryans. But it's possible Coleman was suppoed to invert with Nnamdi and he forgot and ended up in the wrong place. Without knowing the call, we know nothing for sure, other than that it wasn't "Nnamdi's man" who caught the pass.

---

I feel bad saying something unkind about Ryans, because he's playing so well, so let's close with one more play that's better for him.

To cut the suspense, I'll say upfront I don't know what this coverage is. I think it's a cover four, with Nnamdi and DRC dropping to quarters, but it's also possible that it's zone on the close side and man up top. If I had to guess, I'd say cover four. Pre-snap:

I drew up the routes at the bottom since that's where the action is. Up top it's outside guy run off, TE and slot run outs underneath him. Beginning of routes:

DeMeco is locked up on his man while DRC is playing off. Flacco's looking right at DRC's receiver:

Damn those non-press coverages that give up the easy crossing routes. Except wait:

DeMeco comes off his receiver (passing him to the safety) and jumps DRC's. Flacco has to pull it down, and if you zoom in on the photo you'll see that was fatal, because T. Cole is about to swoop in from the blind side. Just a great play all around, and an indication of why we don't just run the same thing over and over.